Bat with foam core insert

ABSTRACT

A composite ball bat comprising a handle, a tapered portion extending from an attachment end of the handle, and a barrel portion extending from the tapered portion to an end-cap end is provided. The barrel portion includes an inner surface and an outer surface. A foam core insert is preferably located within the barrel portion so that it is friction fit within the inner surface of the bat. The specific strength of the foam core insert may be 40 kNm/kg or more, and the specific modulus of the foam core insert may be at least 1,000 kNm/kg. The foam core insert is preferably less than 0.5 g/cc and preferably has a compressive strength greater than 16,500 kPa.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/732,539, filed Sep. 17, 2018, which is hereby incorporated by reference in its entirety.

FIELD OF INVENTION

The present invention relates generally to a ball bat for use in diamond sports such as baseball and softball. More particularly, the present invention relates to a bat having a foam core insert in its barrel portion. The foam core of the bat's barrel portion allows the bat to be stiff but also lightweight.

BACKGROUND OF INVENTION

Numerous attempts have been made to improve the performance of a bat used in diamond sports like baseball and softball. The performance of a bat is generally based upon the weight of the bat, length of the bat, and the impact response of the bat at and during impact with a ball. Lighter weight bats typically allow a hitter to generate a greater bat speed, thus allowing for a greater batted ball speed when a player strikes a ball. As a result, much of the focus for improvements in bat technology has been on reducing the weight of a bat.

Often bat manufacturers attempt to decrease bat weight by utilizing lightweight metal structures. Because those bats use metal, the overall weight of the bat is still not dramatically affected.

The sweet spot of a bat may be many inches in length, depending on the construction of the bat. The sweet spot generally includes a point of maximum performance, at which a batted ball leaves the bat with the highest exit velocity compared to the rest of the sweet spot of the bat. The point of maximum performance is often approximately four to eight inches, and usually five to seven inches, from the end cap end of the bat barrel.

As the prior art bats have increased the performance in this area, many sports regulatory agencies have placed performance and/or configuration restrictions on the bats. For example, most regulatory bodies set a maximum performance level of a bat when a ball impacts the point of maximum performance of that bat, even as the bat “breaks in” during use. Typically, this impact performance level is measured by the exit velocity of the ball off the bat right after impact.

To create bats that meet the reduced performance level requirements, many bat makers have added stiffer materials within bat barrels. Generally, metal rings are inserted into the barrel to help offset some of the trampoline effect of the barrel of a bat during a ball strike. Foam is sometimes inserted into the barrel as well, so as to help position such metal rings within the barrel. There have also been attempts to use foam materials within a bat's barrel portion in place of metal rings, in order to reduce the bat's weight. However, in order to provide additional strength, these foam materials often have a high density that is relatively heavy and contributes too greatly to the weight of the bat. Such foam materials used in the prior art are typically placed in the sweet spot of the bat. Foams with a lower density have less weight, but generally provide insufficient strength to be useful.

SUMMARY OF THE INVENTION

Disclosed herein is a bat for striking a ball. The bat includes a handle portion at a proximal end and a barrel portion at its distal end with a tapered portion therebetween. The sweet spot of the bat is preferably positioned along the barrel portion, and an end cap is preferably located at the end portion of the barrel portion at its distal end.

The barrel portion preferably includes a high strength foam core insert having a high strength to weight ratio and is positioned at or near the bat's sweet spot. The foam core insert may be substantially circular in shape and may be either adhered to an inner circumference of the bat's barrel or pressed into place by a friction fit. As such, in a preferred embodiment, the foam insert may be pushed through the distal portion of the bat toward the proximal portion of the bat until it reaches the sweet spot. When the foam insert is secure, it is preferably substantially perpendicular to walls of the bat's barrel.

This high strength foam core material preferably provides structure to a composite or aluminum bat barrel that enables thinner bat walls to produce an overall lighter weight bat that will still pass regulatory standards such as the rolling tests described above.

The specific strength of the foam core materials under a compression test may be 40 kNm/kg or more. The specific modulus of the same foam core materials under a compression test may be at least 1,000 kNm/kg. The density of the foam core materials is preferably less than 0.5 g/cc and has a compressive strength greater than about 16,500 kPa, or about 2400 psi. In preferred embodiments, the foam may be polyurethane-based or it may be a polymethacrylimide (PMI) foam. Other foam compositions having high strength but low weight are also contemplated.

DESCRIPTION OF THE DRAWINGS

For a better understanding of the various embodiments of the present invention, reference may be made to the accompanying drawings in which:

FIG. 1 is an exploded view of an example embodiment of a bat with a foam core insert exploded therefrom; and

FIG. 2 is a cross-sectional view of the bat of FIG. 1 with a foam core insert in its barrel portion.

While the disclosure is susceptible to various modifications and alternative forms, a specific embodiment thereof is shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description presented herein are not intended to limit the disclosure to the particular embodiment disclosed, but to the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures.

Referring to the drawings, FIG. 1 illustrates an exploded view of a ball bat 1, the components and construction of which will be described hereinbelow. As shown in FIG. 1, like other prior art bats known and understood in the art that are used in diamond sports like baseball or softball, the bat 1 includes a tapered portion 5 and a barrel portion 10. Preferably, the tapered portion 5 is near a handle portion 15 of the bat 1, while the barrel portion 10 of the bat 1 extends from the tapered portion 5 to an end-cap 20 of the bat 1. Like prior art bats, the barrel portion 10 is intended to be the portion of the bat 1 that strikes a ball when the bat 1 is used.

The barrel portion 10 of the bat 1 may include a foam core insert 25 contained within the barrel portion 10 of the bat 1. More particularly, the foam core insert 25 is located near a sweet spot 30 of the barrel portion 10, generally regarded as the location of the bat 1 where struck balls have the highest exit velocity. While the sweet spot 30 is illustrated as approximately six inches from the distal portion 20 of the bat 1, it may be located more distally or proximally than in the illustrated embodiment. In preferred embodiments, the sweet spot 30 is located five to seven inches from the distal portion 20.

Turning now to FIG. 2, when the foam core insert 25 is inserted into the barrel portion 10, an outer circumference 35 of the foam core insert 25 substantially abuts inner wall 40 of the barrel portion 10. The abutment of the outer circumference 35 with the inner wall 40 preferably creates a friction fit such that the foam core insert 25 is firmly stabilized in the sweet spot 30. When the foam core insert 25 is inserted into the bat 1, and is friction fit so that it is positioned as illustrated in FIG. 1, it is substantially perpendicular to the barrel portion 10 of the bat 1. In some embodiments, the foam core insert 25 may be adhered to the inner wall 40 by glue, epoxy, or another suitable adhesive, or by other structural engagements.

In a preferred embodiment, the foam core insert 25 is made of polyurethane foam, but in alternative embodiments, it may be composed of a polymethacrylimide (PMI) foam. Other foam compositions having high strength but low weight are also contemplated that provide structure to the barrel portion 10 but also that enable thinner bat inner walls 40 to produce an overall lighter weight bat.

The specific strength of the foam core insert 25 under a compression test may be 40 kNm/kg or more. The specific modulus of the same foam core insert 25 under a compression test may be at least 1,000 kNm/kg. The density of the foam core insert 25 is preferably less than 0.5 g/cc and preferably has a compressive strength greater than about 16,500 kPa, or about 2400 psi. In the illustrated embodiment, the foam core insert 25 is approximately one and a half inches thick, but in alternative embodiments could be thinner or thicker so long as it retains its high strength and low weight properties.

In alternative embodiments, foam core inserts such as the foam core insert 25 may vary in quantity, location, composition, and/or thickness. Such embodiments may be tailored to fit the particular size, performance, and/or requirements or preferences of any given bat.

From the foregoing, it will be seen that the various embodiments of the present invention are well adapted to attain all the objectives and advantages hereinabove set forth together with still other advantages which are obvious and which are inherent to the present structures. It will be understood that certain features and sub-combinations of the present embodiments are of utility and may be employed without reference to other features and sub-combinations. Since many possible embodiments of the present invention may be made without departing from the spirit and scope of the present invention, it is also to be understood that all disclosures herein set forth or illustrated in the accompanying drawings are to be interpreted as illustrative only and not limiting. The various constructions described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts, principles and scope of the present invention.

As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required.”

Many changes, modifications, variations and other uses and applications of the present constructions will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow. 

What is claimed is:
 1. A ball bat comprising: a handle having a knob end and an attachment end; a tapered portion extending from the attachment end of the handle; a barrel portion extending from the tapered portion to an end-cap end, wherein said barrel portion includes: an inner surface; an outer surface; and a foam core insert secured within the inner surface of the barrel portion, wherein the foam core insert has a specific strength of 40 kNm/kg or more.
 2. The ball bat of claim 1, wherein the foam core insert has a specific modulus of at least 1,000 kNm/kg.
 3. The ball bat of claim 1, wherein the density of the foam core insert is less than 0.5 g/cc.
 4. The ball bat of claim 1, wherein the foam core insert is made of at least one of a polyurethane foam and a polymethacrylimide foam.
 5. The ball bat of claim 1, wherein the foam core insert is secured in the barrel portion by an adhesive.
 6. A ball bat comprising: a handle having a knob end and an attachment end; a tapered portion extending from the attachment end of the handle; a barrel portion extending from the tapered portion to an end-cap end, wherein said barrel portion includes: an inner surface; an outer surface; and a foam core insert secured within the inner surface of the barrel portion, wherein the foam core insert has a specific modulus of at least 1,000 kNm/kg.
 7. The ball bat of claim 6, wherein the foam core insert has a specific strength of 40 kNm/kg or more.
 8. The ball bat of claim 6, wherein the density of the foam core insert is less than 0.5 g/cc.
 9. The ball bat of claim 6, wherein the foam core insert is made of at least one of a polyurethane foam and a polymethacrylimide foam.
 10. The ball bat of claim 7, wherein the foam core insert is secured in the barrel portion by an adhesive.
 11. A ball bat comprising: a handle having a knob end and an attachment end; a tapered portion extending from the attachment end of the handle; a barrel portion extending from the tapered portion to an end-cap end, wherein said barrel portion includes: an inner surface; an outer surface; and a foam core insert secured within the inner surface of the barrel portion, wherein the density of the foam core insert is less than 0.5 g/cc.
 12. The ball bat of claim 11, wherein the foam core insert has a specific strength of 40 kNm/kg or more.
 13. The ball bat of claim 11, wherein the foam core insert has a specific modulus of at least 1,000 kNm/kg.
 14. The ball bat of claim 11, wherein the foam core insert is made of at least one of a polyurethane foam and a polymethacrylimide foam.
 15. The ball bat of claim 14, wherein the foam core insert is secured in the barrel portion by an adhesive. 